Preparation of dry nonhygroscopic crude lactose



Patented Aug. 9, 1932 This invention has duction of dry, non-hygroscopic crude lactose or albumen free whey powd he solids of fresh sweet milk consist chiefly of at, casein, albumen, lactose or milk sugar and mineral salts.

he fat is separated as cream and leaving skim milk containing the remaining milk solids.

Casein is usually separated by allowing the skim milk to sour by the conversion bacterially of a part of the lactose into lactic acid and then applying heat to the conversion mass.

Albumen may be precipitated by the application of heat and h precipitation takes p ace whether the milk or whey is acid or not, although, the physical character of the recipitate formed is largely affected by the de gree of acidity.

he resulting whey, and albumen have been eliminated, is reduced to dryness it is hygroscopic and becomes sticky when exposed to the air.

Furthermore in the manufacture of all cheese whey results. 100 parts of natural milk will yield about parts of cheese and leave 90 parts of Whey. All such whey contains a considerable amount of acid, especiallyif the cheese made is of the ordinary American cheese variety. Also, the cheese whey will sour rapidly after being made, and thus it is found that common whey contains from 0.40% to 0.75% acid.

5 have found that the cause of the hygroscopic property of dry lactose formed from whey is the lactic acid conta ned therein and. if such acid is substantially eliminated y neutralization, the resulting dry lactose is substantially non-hygroscopic.

ly avoided by promptly separating the cream from the sweet milk an d tb en equally promptly precipitating the casein by means of a errnent. such as rennin or pepsin.

l lmost universally. however. the precipitation of the commercial casein is brought about by acid. usually lactic acid produced in the milk from the lactose by bacteria. The

until much above 150 F after the fat, casein sively contract and harden as the temperature is continued and/or increased. 65

-.lbumen does not around 146 to 127 F. and cipitation takes place whether ent or not.

ence, in order to prepare casein substantially free from. albumen the milk should'not, prior to the separation of the casein, be heated -This prohibition applies not merely to the degree of heat used in precipitating the casein, but also to the tempasteurizing the sweet or low preacid is presat which casein is precipitated 1S ordinarily around 0.30 to 0.35% total acidity. Usually higher acidities are in the case of skim-milk.

bbery masses are produced even with acidities over 0.60 to 0.65% unless e milk is violently agitated while heated unless the acidity is exceptionally high, say

.5 to 2% calculated as lactic acid.

sually, therefore. for separating the casein 0.50 to 0.60% total lVhile albumen begins to precipitate at .e precipitation below 100 is relatively slow and prefer to heat to or more to bring about the precipitation. ter the casein has been removed with and heat. the whey remaining will have an acidity of about three-fifths that of the i But the acidity in the whey increases rapidly. due to lactic acid bac- I have further found that the physical character of the albumen precipitate from whey is great y affected by the acidity of the whe With acidities around 0.40 to 0.60% total acidity the albumen is finely divided form not readily separated we from acid is largely or to heating to p latter separates curds w ic rise to the surface of the whey and may be readily skimmed 0 the whey. If, on the other hand, such wholly neutralized, prior the albumen, the

. Hence it is desirable to neutralize the acid of the whey prior to the se )aration of the albumen and then promptly follow such separation with the desiccation of the albumen free whey to avoid further production 0 lactic acid.

To obtain dry non-hygroscopic lactose the total acidity of the whey before heating to remove the albumen should not be greatly in excess of 0.10% and it is better to have it as low as After the albumen has been precipitated out the remaining liquid will show about 0.02 to 0.03% acid.

This may be accomplished by the addition of any suitab e alkaline material. lime or example, in the requisite quantity to neutralize the acid present.

The desiccation of the whey is preferably carried out by spraying the albumen free y into a current of heated air not on y for convenience in obtaining a pro not that does not require subsequent drying and grinding. but also because in such drying process her change there is little or no inversion or ot in the lactose.

When whey is powdered containing both the albumen and the acid the resulting powder is very prone to develop whereas with the albumen removed acid neutralized the powder retains its sweet characteristics, and is suitable foi uman food purposes.

Preferably the procedure is to start with common cheese whey, or commercial casein whey, thence allow the whey to sour to a total 0.40% to 0.00% measured as lactic acid. then to neutralize the acidity to about 0.10% total acidity and l 0 185 F. or more to precipitate the albumen, skim an strain. filter or centrifuge to remove the finer particles of remaining albumen and finally the albumen ree whey. After the acid has been neutralized completely, or to the desired extent steam is directly into the whey until the latter is b ing hot. Steam is then shut off of whey allowed to remain quiet for a few minutes or until curds have floated to the surface. These curds are then skimmed off and cooled to prevent souring. This albuminous curdy material being rich in food constituents is then ready to be user as a human food especially by being incorporated with other cheese.

The aqueous solution remaining after the albuminous curd has been removed, is then run through a fine cloth strainer or through .a centrifugal clarifying device moval of the last traces of curdled albumen.

oil-

h The clear 1 reducing own q and the tank for the reremaining then consists of 0.04% mineral salts, 0.03% 'titratable acid and the balance water.

liquid is now ready to be dried to a powder by The powder any su table means. will be found to be free from bad odor an have only slight hygroscopicity and be almost ure white in color.

If, because of adverse storage conditions, or by deliberate intent, the powdered lactose does become caked due to the small amount of moisture absorbed, it is desirable to allow it to fully satisfy its affinity to become quite completely solidified, an then to pulverize the cake in a suitable mill, when it will be found grains will not again form in The final product consists of about 88 to 90% lactose, 9% mineral salts and the balance moisture. It is read'ly soluble, of good taste and valuable for making bakery products and confectionery.

The clear whey about 5% lactose, total numerous details of the without departing from the spirit of this invention an patent otherwise than as necessitated rior art.

I claim as my invention:

1. The hcreindescribed method of reducing whey to powdered form, which comprises removing albumen from the whey, extracting moisture therefrom, subjecting the drie product to moisture to satisfy its affinity therefor and forming the product into a cake and finally reducing the cake to powdered form.

2. The herein described method of reducing whey to powder form which consists in removing albumen by boiling and skimming the whey, extracting the moisture of the whey, subjecting the product to pure, odorless moisture to satisfy its affinity therefor and form the product into a cake, and finally the cake to powder form.

3. The herein described method of producing an odorless powder from whey which consists in boiling the whey to bring the albut to the surface thereof, subseuently removing the albumen, neutralizing the whey, thereafter extracting the moisture of the whey to form a powder, subjecting the iowder to the action of water to satisfy its aflinity therefor and produce a cake, an finally reducing said cake to a finely comminuted state.

In testimony scribed my name at Chicago,

Ill.

ROBERT M. WASHBURN.

for moisture and that the powdered 

